China has for the first time urged the Syrian regime to deliver on its much-promised reforms, in a move that some observers see as a sign of waning patience with its embattled ally.

A staunch supporter throughout the six-month uprising, Beijing said on Tuesday that Bashar al-Assad's government must "respond to the Syrian people's reasonable expectations".

The announcement by the foreign ministry appears to be a nod to the anti-government movement, which insists it has remained largely passive in the face of an intensive military crackdown. The move is also being seen as a message to Damascus that Beijing is diverging from the Syrian narrative, which suggests the uprising is the work of foreign-backed terrorists.

"China is highly concerned about the situation in Syria, is against the use of violence, and we hope not to see any more bloodshed and casualties," a foreign ministry spokesman, Liu Weimin, said. "The Syrian government should move faster to honour its reform pledges and quickly initiate and push forward the inclusive political process with the broad participation of all parties."

The move comes several days after Russia also publicly shifted its position, offering more strident criticism of the regime and demanding that Assad either reform or quit. Both countries had been heavily criticised by Europe and the US for vetoing a bid in the UN security council to threaten further sanctions. Russia has maintained its strategic alliance with Syria from the cold war and China is looking to consolidate a foothold in the region.

Beijing and Moscow had also been critics of the Nato intervention in Libya and vetoed a security council bid to prevent a repeat in Syria.

The six-month revolt in Syria has crippled the economy, destroyed tourism, led to nearly 3,000 deaths and polarised the various groups inside the country, which has been ruled by the pan-Arab Ba'ath party, enforced by the 40-year rule of the Assad family. How to deal with the ongoing violence continues to trouble Sunni Arab states and Europe, who fear an inexorable slide towards civil war if Assad does not introduce a comprehensive reform programme, or cede power to a nascent opposition.

The 46-year-old president has repeatedly shown he has no intention of leaving. His foreign minister, Walid al-Muallem, this week warned of "severe" measures against any country that recognised a new opposition body, which aims to unite dissidents inside and outside of Syria and cast itself as a new representative group. Libya's National Transitional Council has already recognised the group and the EU welcomed it as a "positive step".

Assad again pledged reforms over the weekend, in particular the establishment of a committee to draft a new constitution.

Syrian security forces continue to besiege the city of Homs, where dissidents are clashing with security forces most days. Large numbers of the city's residents have fled to Lebanon since the weekend fearing a full-scale invasion by troops who have encircled the city.